The Study On The Relationship Between Vitamin D Receptor And Papillary Thyroid Carcinoma

Papillary thyroid carcinoma (PTC) is the most common malignant tumor in the endocrine system, and the incidence has gradually increased. At present, the vitamin D receptor (VDR) has been of great concern in the field of cancer prevention. Previous studies have found that the expression of VDR in breast and colon cancer is significantly reduced. However, the relationship between VDR and papillary thyroid carcinoma is not clear. To address this issue,we have examined the expression level of VDR in the thyroid tissue from62patients with papillary thyroid carcinoma. Patients were divided into3stages according to the staging system of American Cancer Society. All the patients did not received any medical treatment before operations. All tissue samples are obtained after clinical and pathological diagnosis. Immunohistochemical assay was used to examin the expression of VDR, cell adhesion markers(p120-catenin and E-cadherin), thyroid differentiation markers[sodium iodide symporter(NIS),thyroglobulin (TG),thyroid peroxidase(TPO), thyroid stimulating hormone receptor(TSHR)] as well as the proliferation markers[proliferating cell nuclear antigen(PCNA)]. The result shows that the expressions of VDR, p120and E-cadherin in the papillary thyroid carcinoma were significantly lower than those in adjacent normal thyroid tissue or were ectopic expressions. The expressions of TG and TPO in the papillary thyroid carcinoma were significantly lower than those in adjacent normal thyroid tissue. In contrast, the expression of PCNA in the papillary thyroid carcinoma was significantly higher than that in adjacent normal thyroid tissue. NIS and TSHR were ectopic expressions of cytoplasm In papillary thyroid carcinoma. The level of VDR expression in patients with lymph node metastasis was higher than that of patients without lymph node metastasis. Decreased levels of VDR were associated with increased size of the tumor. Patients with advanced stages of the tumor displayed decreased expressions of VDR, TG and TPO, and increased expression of PCNA. The expressions of p120and E-cadherin in the tumor with negative VDR expression were lower than that in the tumor with positive VDR expression. Based on these results, we suspect that decreased VDR expression is associated with decreased expression of p120and E-cadherin as well as increased tumor growth, invasion and metastasis.